A conventional device for determining a position which uses a Global Positioning System (G.P.S.) is well known. In such a system, a person can determine the longitude and latitude of their position by receiving radio signals from a plurality of satellites with a G.P.S. receiver. Then, the person can determine their position by comparing a map with the longitude and latitude information from the receiver. One example of such a well known system is a commercially available LORAN navigation system.
However, it is not easy to determine one's position by comparing a map with longitude and latitude information. It is accordingly necessary for the person to have a particular level of skill.
FIG. 2 illustrates a block diagram of the function of a conventional driving guide device for a vehicle which uses a G.P.S. receiver 1. Map data is stored in CD-ROM 2 or other memory media (e.g., magnetic tapes). The position from G.P.S. receiver 1 is compared by central operational portion 3 with the map data of CD-ROM 2 and the longitude and latitude information from recover 1, and position is indicated on display 6 together with the map through portrait memory 4 and indication control portion 5. Accordingly, one's position can be easily recognized. An example of such a system is the commercially availabel Bosch travelpilot.
However, it is necessary in the above driving guide device for a vehicle to use an expensive memory media, (e.g., CD-ROM) which can memorize a large quantity of information. Such memory media are very expensive, and devices using these memory media are not in widespread use.